The present invention relates to depth-gauging vision systems and more particularly to such a system which utilizes the reflected image of a projected feature on the object to determine the object's distance and orientation.
One of the significant problems in intelligent robotics is the automated determination of information about the immediate vicinity of the robot. Many tasks that the robot can perform have the need for vision, and some tasks require three-dimensional information about the work area or workpiece. Such tasks include assembly operations and automated inspection for quality control. Another less traditional use of three-dimensional vision is to provide information required for navigation of a mobile robot in a semi-structured or unstructured environment.
The approach currently used in providing navigation information to a mobile robot has been limited to multiple camera convergence vision systems. In such a system, images of the scene are taken by several cameras. The images are analyzed, and objects common to each camera are noted and compared. By convergence triangulation, the distances to objects in the field of view of the system can be deduced. Stereoscopic vision techniques and structured light techniques have been and are being used to guide robotic arms in welding operations as well as in other assembly operations. Automated inspection also often requires such vision systems.
To analyze the depth structure in such a stereoscopic vision system, the following operations must be performed. First of all, images from two or more cameras must be taken and stored. Then, distinct, unambiguous features must be identified in each of the images. Finally, the features must be correlated among each of the camera images and convergence triangulation operations are performed on each of the features common to two or more images. The known stereoscopic vision systems require substantial image processing capability to extract the depth information. Such systems are thus computationally complicated and expensive.
It is therefore an object of the present invention to provide apparatus for determining depth and orientation of an object which substantially reduced the computational processing required.
Yet another object of the invention is depth gauging apparatus which is more accurate than the known stereoscopic systems.
Yet another object of the invention is depth-gauging apparatus which requires but a single camera.